Maintaining the 2018 Lexus RC350 requires a disciplined approach to fluid selection, particularly given its naturally aspirated 3.5L V6 engine code 2GR-FKS. This powertrain demands precise viscosity and filtration to ensure the high-stress components of the variable valve timing system and turbocharging (where applicable in related engines) remain lubricated under extreme thermal loads. Using the correct oils, filters, and fluids is not just about following a manual; it is about extending the vehicle’s operational life, maintaining fuel economy, and preserving the premium driving character Lexus is known for.
Recommended AMSOIL Products
- AMSOIL Signature Series 0W-20 100% Synthetic Motor Oil – Delivers 75% more engine protection against horsepower loss and wear, offering a service interval of up to 25,000 miles for drivers who want the ultimate in performance.
- AMSOIL Extended-Life 0W-20 100% Synthetic Motor Oil – Provides 37% more cleaning power to keep the engine running smoother and offers 20,000 miles of guaranteed protection between changes.
- AMSOIL OE 0W-20 100% Synthetic Motor Oil – A cost-effective solution that fights sludge and deposits, suitable for those looking to match or exceed OEM mileage specifications.
- AMSOIL 0W-20 100% Synthetic High-Mileage Motor Oil – Formulated with unique chemistry for vehicles with over 75,000 miles to reduce sludge and boost cleaning power.
- AMSOIL Oil Filter – Offers 99 percent filtering efficiency at 20 microns to help reduce engine wear and provides extended service life to match synthetic oil intervals.
- WIX Oil Filter – A robust alternative matching OEM specifications for standard service intervals.
- AMSOIL Passenger Car & Light Truck Antifreeze & Coolant – A ready-to-use 50/50 pre-mix formulation providing up to 150,000 miles of protection for the cooling system.
- AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid – Withstands the rigors of high temperatures and heavy use, ideal for the A760H or AA81E transmissions found in the RC350.
- AMSOIL SEVERE GEAR® 75W-85 100% Synthetic Gear Lube – Specifically recommended for the rear standard differential to control thermal runaway and protect against wear.
- AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid – Ensures excellent ABS responsiveness and provides a stable viscosity over a wide temperature range for superior stopping power.
The heart of the 2018 RC350, the 2GR-FKS engine, operates with tight tolerances and relies heavily on stable oil viscosity to manage the variable valve timing system. The engine requires approximately 6.8 quarts of fluid when a filter change is included, with a specific drain plug torque of 30 ft-lbs. While the 0W-20 grade is the primary recommendation for optimal fuel economy and cold-start protection, understanding the nuances of synthetic versus conventional blends is vital for owners who push their vehicles to the limit. The Signature Series motor oil stands out for its ability to maintain viscosity stability under extreme heat, a common stressor in the sport coupe segment.
Filtration is equally critical. The AMSOIL Oil Filter is engineered with a higher dirt-holding capacity than standard paper filters, which is crucial for maximizing the benefits of extended oil change intervals. By filtering out smaller contaminants more effectively, the filter helps reduce wear on camshafts, lifters, and the turbocharger components often found in modern, efficient engines. For those preferring alternative brands or needing a backup solution, the WIX Oil Filter also provides a robust option for standard service intervals, matching the OEM specification requirements.
Cooling and Transmission Durability
The cooling system in the RC350 requires a specific fluid capacity of 10.1 quarts. Using the wrong coolant can lead to corrosion of aluminum components within the block and radiator. The AMSOIL Propylene Glycol Antifreeze and Engine Coolant is a concentrated option for those who prefer to mix their own, offering protection for up to 150,000 miles. Alternatively, the AMSOIL Passenger Car & Light Truck Antifreeze & Coolant is a ready-to-use ethylene glycol formula that exceeds OEM requirements and is free from phosphates and silicates that can clog systems over time.
Transmission health is often overlooked until problems arise. The RC350 is equipped with either the 6-speed A760H or the 8-speed AA81E automatic transmission. The AMSOIL Signature Series Fuel-Efficient 100% Synthetic Automatic Transmission Fluid is designed to handle the thermal stress of stop-and-go traffic and spirited driving. It remains fluid in sub-zero temperatures and resists oxidation, preventing the formation of sludge that can clog valve bodies. For the manual transmission or specific limited-slip differential applications, the SEVERE GEAR® 75W-90 offers superior protection against wear and controls thermal runaway. The 75W-85 variant is specifically tailored for the rear standard differential, ensuring smooth operation of the limited-slip components.
Safety on the road is paramount, and the braking system relies on fluid integrity. The AMSOIL DOT 3 and DOT 4 100% Synthetic Brake Fluid offers a much higher boiling point than conventional DOT 3 or 4 fluids. This reduces the risk of brake fade during heavy usage, such as canyon runs or track days, and ensures that the ABS system remains responsive even after repeated braking cycles.
Additional Fluid Care and Performance Additives
For owners looking to optimize fuel economy and engine cleanliness beyond the oil change, the AMSOIL P.i. Performance Improver is a powerful solution. This gasoline additive can restore up to 14% horsepower and clean GDI (Gasoline Direct Injection) fuel injectors to 100% flow rate after just one tank. This is particularly beneficial for modern engines where carbon buildup on intake valves is a common issue. Additionally, for seasonal storage, the AMSOIL Gasoline Stabilizer helps keep fuel fresh for up to 12 months, preventing varnish and gum buildup that can clog carburetors and fuel systems.
Cleaning and protection extend to the undercarriage and body as well. The AMSOIL Engine Degreaser is a professional-strength formula that quickly removes the toughest grease and grime from engine surfaces. For exterior care, the AMSOIL Miracle Wash Waterless Wash and Wax Spray provides a fantastic shine and protective finish without the need for soap or water, making it an excellent choice for quick cleanups that keep the vehicle’s finish in pristine condition.
About the Vehicle
The 2018 Lexus RC350 stands as a testament to the brand’s commitment to blending luxury with performance. As part of the Lexus RC series, which debuted as a coupe variant of the IS sedan platform, the RC350 is designed for drivers who refuse to compromise on style or driving dynamics. It occupies a unique space in the market, bridging the gap between a traditional luxury sedan and a dedicated sports coupe. The vehicle is powered by the renowned 2GR-FKS 3.5-liter V6 engine, a naturally aspirated powerplant known for its smooth power delivery, high-revving capabilities, and reliability. This engine produces robust horsepower figures that provide ample acceleration, allowing the RC350 to hold its own against more expensive European competitors in the sport coupe segment.
The RC350’s chassis and suspension tuning are sport-tuned to offer precise handling and a responsive steering feel, qualities that are highly prized by enthusiasts. The vehicle’s interior is crafted with the meticulous attention to detail typical of Lexus, featuring high-quality materials, comfortable seating, and advanced technology integration. For the 2018 model year, the RC350 was available in various trims, including the standard RC350, the F Sport with its aggressive styling cues and upgraded suspension, and the RC350 AWD which offers added traction for all-weather driving. The platform’s origins in the Japanese automotive tradition are evident in its build quality and engineering finesse.
Despite its reliability, the RC350 can benefit from proactive maintenance, especially as it ages. Owners often report issues related to engine oil consumption in high-mileage examples, which can be mitigated by using high-quality synthetic oils designed to seal aging rings. Another common area of concern is the cooling system, where coolant degradation over time can lead to overheating issues that damage the engine. Using a premium antifreeze like the AMSOIL Propylene Glycol Antifreeze can help prevent these costly repairs. Furthermore, the transmission fluid can sometimes degrade, leading to harsh shifting or delayed engagement; regular fluid changes with a high-performance synthetic can restore smooth operation and extend transmission life. Finally, brake fluid hygroscopy, where the fluid absorbs moisture over time, can lower the boiling point and lead to brake fade. Switching to a high-performance synthetic brake fluid ensures consistent pedal feel and stopping power, keeping the RC350 safe and responsive throughout its service life.
By adhering to a rigorous maintenance schedule and utilizing the recommended AMSOIL products, owners can ensure that their 2018 Lexus RC350 delivers the performance, luxury, and reliability that the Lexus brand promises. Whether it is for daily commuting or weekend driving, the right fluids make a significant difference in the vehicle’s longevity and driving experience.